Improvement in i



' UNITEDy STATES PATENT OFFICE.

E. F.HOVARD, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT IN ll'AHlNERY FR FINISHING RIM-BASES 0F ORDNANCE.

Specification forming part of Letters Patent No. 40,039, dated September 22, 1863.

.To @ZZ whom it may concern:

Be it known that I, E. F. HOWARD, of Boston, county of Suffolk and State of Massachusetts, have invented a Machine for Finishing the Rim-Bases of Ordnance; and l do hereby declare that the following, taken in connection with the drawings which accompany and form part of this specification, is a description of my invention sufficient to enable those skilled in the art to practice it.

ln finishing the surfaces of metal ordnance the cylindrical parts of the body of the cannon are turned or cut down in a lathe, excepting that portion of the said surfaces lying between the trunnions of the gun, which parts are planed downin a-planer. The trunnions, being cylindrical, are turned down in the same man-ner, and these processes finish the outer surfaces of the gun, except the rim-bases or those portions connecting the trunnions to the barrel or body of the piece. Where these are made cylindrical they can be cut down by a lathe and planingmachine, but where they curve from the shouldered ends thereof adjacent to the trunnion to and Hush with the surface of the gun some other means are necessary to nish or cut down said surfaces. In the manufacture of pieces having such rimbases they are generally chipped down oy hand labor, the operation being very laborious, lengthy, and expensive. l have sought, therefore, to adapt a mechanism to perform this work, and my present invention relates to and consists in a method of automatically operating a cutting-tool to cut the curved surfaces of these rim-bases.

The mechanism embodying my invention is shown in the accompanying drawings, Figure l representing a plan of the same, and Fig. 2 a central section taken on the line x y of Fig. 1. Fig. 3 shows the arrangement of gears for operating the mechanism.

A denotes a portion of the barrel or body of the cannon, from the side of which the trunnion B extends, the trunnion and body being joined by the rim-bases O. The trunnion extends into a chuck or collar, D, the outer surface of which is made cylindrical and Hush with the circumference of the outer edge of the rim-base, or to the circumference which said rim-base is to have when nished. This chuck is fixed upon or forms the end of a stationary shaft, E, and when chucked to the shaft the axial line of the trunnions and shaft E is the same, said axial line being perpendicular to the axis of the gun-barrel. This shaft carries or has fixed upon it a stationary plate, F, and a sliding pattern-plate, G, and parallel to these plates a camplate or ring, H, is placed, as seen in Figs. 1 and 2. Between this ring H and the chuck D the shaft E bears a loose or sliding gear, I, from the rear face of which an ear or projection, a, extends. A rocking lever or tool-holder, lc, turns on a pin, b, fixed to the projection a. The front end of this holder carries the tool or cutter c, while its rear end rests upon and is operated radially or to and away from the axial line of thetrunnions by the surface of a cam, former, or pat-tern L, which extends out from the front face of the sliding plate Gr, as seen in Figs. l and 2. From the projection a an aim, d, extends, such arm carrying a campin, e, which extends into and is Worked by a grcoved cam, f, extending around the inner surface of the camring H. This cam gives a reciprocal longitudinal movement vto the cutter toward and away from the axial line of the barrel of the gun.

Rotary motion is given to the gear I, and

thence to the cutter or tool c, by a gear, M,

on a shaft, N, or in any other convenient manner. Rotation of the gear I carries the cutter around the rim-base in a circular direction. As the cutter rotates, it is held in proper position to cut the required curvature on the rim-base parallel to the axis of the trunnion by the bearing of the rear end of the tool-holder on the patternsurface L, and parallel to the axis of the gun-barrel by the grooved cam f. The reciprocal movement of the tool produced by the cam j' at each revolution is not over the whole width of surface of the rim-base from the line h n to the line 7.a m', but only over a portion of said width of surface, the tool having a progressive movement given to it toward the axis of the gun. This movement is produced as follows: From the fixed plate F on the shaft E a series of screw-shafts, g, extend, connect-ing said plate with the camfplate H, the screws working through female threads in said cam-plate. Gears are fixed upon and rotate said screwshafts, and these gears are connected together by intermediate gears, P, running loosely on rods or shafts h, xed to the plate H, and sliding through the plate F.

A gear, Q, on the shaft N meshes inio and' actuates one of the gears o, and thereby the train of gears o and P and screw-shafts g, ro-

tation of-the gear Q in the direction denoted by the arrow in Fig. l causing the movement of the cam-plate l' and cutter c toward and perpendicular to the axis of the cannon. As the cutter moves forward onto the enlarged part or portion of the rim-base, or toward the part thereof which joins the body of the gun, it is guided by the contact ot' the opposite end ofthe tool-holder, which impinges againstthe diminishing contour of the pattern surface L, and the movement of the tool or cutter by the cam-groove j' is so regulated that when the camplate or ring H is completing its outward movement the cutter shall traverse horizontally from the plane s i to the plane 7c m, and from the plane 7c m to the plane u t, the contour of the pattern L regu` llating as the cutter f'eeds up its distance from the center or axial line of the trunnion. The plate G',\vhich bears the pattern L, is provided with nuts or screwthreads, through which the screw-shafts g work, said screwshaft being provided adjacent to said nuts with left-handed screw-threads, so that when the rotation of the gears feeds the cam-plate H forward or toward the rim-base the patternplate G and its pattern L shall receive a cor responding retrograde movement. By this means while the tool is fed forward an inch onto the 1imbase,or toward the axis ofthe gun, the pattern falls back an inch, thereby separating the pattern and cam-plate two inches. rIhe purpose ot' this is to give the pattern lengthwise a longer or more gradual curve than the curve to be given to the rimbase, so that the guiding end of the toolholdrr, in its reciprocal movement over the cam-surface, shall have a less abrupt curvature to move over than if the pattern remained stationary and its curvature was the exact reverse of the curvature of the rim-base. This feature, however, is not essential to the working of the mechanism7 as the pattern may be so curved as to operate the tool without any such rear movement.

rlhus it will be seen that in carrying out my invention I give to the cuttingtool automatic movements, as follows: A rotary movement around the rim-base, a radial movement parallel to the facel of the trunnion, a reciprocating longitudinal movement parallel to the axis ot' the trunnions,and al progressive movement toward the axis of the gun. f

I do not confine my invention to the precise arrangement of the gears, and other parts of the mechanism, as shown, as the same may be altered or modified as circumstaneesrequire.

I claim- 1. Finishing or cutting the rim-bases of ordnance. by the employment of a cutting-tool guided automatically by a pattern, cam, rotating and feeding mechanism, substantially as described.

2. Giving to the pattern L the reverse movenient in the manner and for the purpose as set forth.

In witness whereof I have set my hand this 17th day of August, A. D. 1863.

EDWARD r. HOWARD.

In presence of- J. B. CROSBY, F. GOULD. 

